Self and james



UNITED STATES IVILLIAM GRIFFITH, OF PITTSBURG,

,PENNSYLVANIA, ASSIGNOR TO HIM- I SELF AND JAMES C. GRAY, OF SAME PLACE.

PROCESS OF PURIFYING MOLTEN IRON.

SPECIFICATION forming; part of Letters Patent N 0. 289,087, dated November 2'7, 1883.

Application filed May 2 To all whom it may concern.-

Be it known that I, "WILLIAM GRIFFITH, of

Pittsburg, in the county of Allegheny and State fine it and remove impurities therefrom. These chemicals may be added or introduced into the molten metal after it has been run from the furnace into the ladle or mold, or they may be added to the metal in Bessemer converters, paddling, refining, open-hearth, cupola, blast, and other furnaces.

I will now describe my invention, so that others skilled in the art may use the same.

When the meta-lhas been reducedto'a molten state in the furnace, sal-soda and ferro-cyanide of potassium are added thereto in about equal proportions. These chemicals unite with the impurities and rise to the top with the slag, leaving the refined and purified metal free to be drawn from the furnace. In the puddling' furnace the chemicals should be added to the metal while it is still boiling and before it comes to nature.

In order that the chemicals may act properly upon the metal, care should be taken that they are placed beneath the surface of the molten metal in the furnace. This may be easily accomplished by inclosing the chemicals in thin metal cases or boxes.

Instead of introducing the sal-soda and ferrocyanide of potassium into the furnace, they may be placed in the ladle, mold, or Bessemer converter before the molten metal is poured therein.

5, 1883. (No specimens.)

The amount of sal-soda and ferro-cyanide of potassium to be added to the metal depends upon the quality of the iron or steel and the amount of impurities, phosphorus,'and other foreign substances contained therein; but for ordinary grades of metal forty-five ounces of sal-soda and a like quantity of ferro-cyanide metal.

The advantages of my invention are that the phosphorus and other foreign substances are removed from the metal, and it is therefore tough and fibrous throughout, and a superior quality of iron may be produced from an inferior quality of metal.

I am aware that sal-soda and ferro-cyanide of potassium have been used separately and in conjunction with various other chemicals in physics for the purification of iron, and in different steps or stages of the process, and do not broadly claim the same; but I am not aware that the said two ingredients have been used conjointly and in the manner hereinbefore specified. Therefore,

claim, and desire to secure by Letters Patent, is

The process herein described for refining and purifying iron and steel, which consists in subjecting the molten metal to the action of salsoda and ferro-cyanide of potassium,in substantially the proportions specified, as and for the purposes set forth.

In testimony whereof I have hereunto set my hand this 19th day of May, A. D. 1883.

\IILLIAM GRIFFITH.

"Witnesses:

W. B. Conwrn,

J. K. BAKEWELL.

of potassium may be used with each ton of Having thus described my invention, what I a compound consisting of the two ingredients, 

